A doomsday device is a weapon that is capable of unleashing destruction on a large scale. Professor Farnsworth has built and/or collected numerous of these devices, but was forced to sell many of them to Hedonismbot when he lost his business to the Scammers.

Professor Farnsworth used a doomsday device to power Bender after regenerating the robot, though Bender was forced to party continuously in order to burn off the excess energy being produced by the battery. Bender eventually refused to party any longer, and nearly exploded as a result of the device overloading. He was swallowed by a Cyclophage before the device could rupture, and the device short-circuited as a result, eliminating its excess energy outputs and turning it into an ordinary battery.

Professor Farnsworth and Hermes Conrad later threw a box full of doomsday devices into a dumpster during a community recycling event at CitiHall.